Polyurethane foams are widely known and used in a variety of applications, such as in the automotive and housing industry. These foams are produced by the reaction of a polyisocyanate with a polyol in the presence of various additives. One such additive is an amine catalyst which is used to accelerate blowing (the reaction of water with polyisocyanate to generate CO2) and gelling (the reaction of a polyol with polyisocyanate).
Disadvantages in using conventional amine catalysts (for example, bisdimethylaminoethylether) in polyurethane foam production include: due to their high volatility, safety and toxicity problems can occur, for example, airborne vapors emitted from such catalysts are known to cause glaucopsia, also known as blue haze or halovision, which is a temporary disturbance of vision clarity; when used in the production of foams used in automotive interior applications, fogging of automotive windshields can occur; and, conventional amine catalysts are generally known to be malodorous.
Examples of pyrrolidine catalysts which have been recently tried include N-aminoalkyl pyrrolidines (U.S. Pat. No. 5,134,217), 3- and/or 4-substituted pyrrolidines (U.S. Pat. No. 5,274,114) and aminomethylpyrrolidine ureas (EP 0877017 B1).
It is an object of the present disclosure to provide new pyrrolidine-based catalysts for use in producing rigid or flexible polyurethane foam and other polyurethane materials which exhibit high catalytic activity, reduce or eliminate glaucopsia, are odor-free and environmentally friendly.